There is a Q&A between John Heald and some corporate VP on Facebook. It says they'll let people attain platinum level under the old rule of 10 cruises if they complete them by 12/31/13.

At least he was honest about some of the changes: Too much laundry was being done for free and overwhelming the hotel staff, too many people were eligible for the repeater party and it was becoming a logistics problem, too many people were using the guaranteed dining time perk, and he said don't be surprised when they tighten up some more in the future as more people climb the membership ladder.